Journalism is one field with a Catch-22: You can't get a job without experience, and it seems like you can't get experience without a job.
Hiring editors want to see published clips. The key is to start small.
One of the best places to start is at a school or college newspaper. Other options are freelancing and internships.
If you have zero journalism background, you should probably take at least a class or do some independent reading about journalism. Besides learning more about how to research and write (or journalism skills other than reporting, such as copy editing or multimedia), it will help to learn about ethics and other standards.
People considering entering the field should be aware that, as of 2007, this is a tumultuous time in the industry. For example, besides the continuing decline in newspaper circulation, ad revenue has also been decreasing, and digital technology is bringing various changes.